Fire alarm

ABSTRACT

A self-contained fire alarm including a horn, a container for a pressurized propellant to sound the horn and self-operating valve means connecting between the horn and the container. The valve means consists of a guided spring-urged valve acting against propellant pressure.

United States Patent William Wagner c/o Watsco Inc. 1800 West Fourth Ave., Hialeah, Fla. 33010 [21] Appl, No. 872,193

[22] Filed Oct. 29,1969

[451 Patented July 6, 1971 172] lnventor [54] FIRE ALARM [56] References Cited UNITED STATES PATENTS 3,310,024 3/1967 McConnell 1 16/124 3,373,764 3/1968 Munn 137/469 3,425,444 2/1969 Jones 137/540 1,212,102 1/1917 Pipe l16/114X 2,051,100 8/1936 Nelson 137/539 X 2,560,523 7/1951 Efford 222/146 H X 2,758,563 8/1956 Bigelow 116/106 2,778,330 1/1957 Jacoby 116/106 2,840,032 6/1958 Reeves 116/112 2,876,935 3/1959 Lindberg 116/112 UX 2,993,466 7/1961 Sklaroffet a1. 116/112 3,002,490 10/1961 Murray 116/124 3,029,981 4/1962 Webster et a1..... 222/3 3,095,851 7/1963 Lager 116/124 Primary Examiner-Louis J. Capozi AttorneyStoll and Stoll ABSTRACT: A self-contained fire alarm including a horn, a container for a pressurized propellant to sound the horn and self-operating valve means connecting between the horn and the container. The valve means consists of a guided springurged valve acting against propellant pressure.

PATENTEU JUL 6 I971 INVENTOR. WILLIAM WAGNER nrromvsw" FIRE ALARM BACKGROUND OF THE INVENTION 1. Field ofthe Invention Fire Alarms.

2. Description of the Prior Art Many forms of fire alarms are known to the art, some of which are electrically powered and some of which utilize fusible members. Most such fire warning devices require external sources of energy or, as in the case of battery-powered alarm systems, require periodic recharging or replacement of the power source.

SUMMARY OF THE INVENTION The present invention provides a fire-activated audible warning system which is entirely selfcontained and requires no dependence upon external or refreshed power supplies. There is accordingly no danger that a failure ofa power supply will incapacitate the alarm.

Briefly, and not be way of limitation, the present invention provides a horn connected by self-activating valve means to a container for a pressurized propellant. The container is located in the critical area for which fire protection is desired and constitutes the sensing mechanism. The horn is located in an area most likely to attract attention. Communication is provided between the container and the horn and the self-operating valve mechanism provides control.

The heat of a fire heats the container and its content and causes a corresponding increase in content pressure. When that pressure exceeds the bias of a spring-urged valve the valve opens and the propellant escapes through the horn and sounds the alarm. The alarm continues until the pressure in the container falls below the spring bias whereupon the spring in a pri mary embodiment of the invention is permitted to close and the alarm stops sounding.

In an example of use of the fire alarm of the present invention, the container is placed adjacent a home-heating furnace. The horn mounts directly to the container separated only by the valve means. Excessive heat caused by a fire or other malfunction of the furnace would sound the alarm.

The container is a sealed unit which is adapted to securely receive the valve means and the housing therefor. In a preferred embodiment the two units are threadedly coupled and a knife edge attached to the valve mechanism punctures a seal on the container. The temperature at which the alarm will sound is determined by the bias of the valve spring.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a side view of the fire alarm of the present inven; tion showing the container and horn coupled together. A mounting bracket is shown in phantom.

FIG. 2 is a cross-sectional view taken across line 2-2 of FIG.

FIG. 3 is a cross-sectional view taken across line 3-3 of FIG.

FIG. 4 is an enlarged cross-sectional view of the valve means of the present invention showing the valve closed.

FIG. 5 is an enlarged cross-sectional view of the valve means, a portion of the horn and a portion of the container to which the valve means is attached.

FIG. 6 is an enlarged cross-sectional view ofa modified embodiment of the valve means of the present invention.

FIG. 7 is a perspective view of the seal-piercing disc.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION Referring to the drawing, fire alarm 10 of the present invention comprises a horn 12 including a housing 14, a pressurized container 16 and valve means 18 connecting between horn 12 and container 16.

Horn 12 includes a vibrating diaphragm or membrane 20 located in accordance with standard practice at the reduceddiameter end of horn 12. Vibration of diaphragm 20 is induced by a high-velocity gas flow occurring between the diaphragm and the small open end of the horn, the space therebetween being relatively small. Diaphragm 20 forms a sealed chamber 22 in conjunction with a portion of housing 14 on the side of diaphragm 20 opposite horn 12. The sealed chamber provides a rebounding compression against diaphragm 20 as the diaphragm is forced into the chamber by the gas flow. The diaphragm is thus provided with a bounce" which provides diaphragm vibration in conjunction with the high-velocity gas flow of the opposite side of the diaphragm.

Valve means 18 comprises a valve seat 26, a valve 28, a valve enclosure 30 and a spring 32 acting between valve 28 and valve enclosure 30 to bias the valve toward its seat 26 and close the valve to fluid flow.

Valve seat 26 is provided with a central bore 34 which is selectively closed at its upper end by valve 28 and which extends through the bottom of the valve seat portion 26 for communication with the content of container 16. Across bore 34 is a disc 36 retained between two washers 38. The portion of bore 34 which is below disc 36 is provided with threads to threadedly engage a cap 38 of container 16.

Disc 36 is provided with a downwardly extending point 40 which is adapted to pierce a seal 42 located within cap 38 of the container upon threaded engagement of the cap and the valve means. When seal 42 is pierced the content of container 16, which is under pressure, is released into bore 34 and bears against valve 28 and the bias of spring 32. Should the pressure of the content of container 16 increase to a point in excess of the bias of spring 32, valve 28 is forced open and the content escapes through enclosure 30 to diaphragm 20 and the small end of horn 12 through communicating holes 44 provided for the purpose in enclosure 30 and housing 14, enclosure 30 sitting within housing 14.

In a first embodiment of the invention it is desired to have valve 28 reseat accurately and automatically upon a reduction of pressure of the content of container 16. Such an embodiment would permit intermittent use of container 16 to accompany intermittent heating and cooling of container 16 or to make the valve means easily reusable. Thus, for example, in this embodiment of the invention fire alarm 10 may be tested by placing container 16 in a container of warm water until the horn sounds and then removing container 16 from the water to permit the container to cool and the horn to stop sounding. It should be noted that this means of testing the fire alarm is entirely feasible and would not quickly exhaust the content of container 16 because the container is in effect self-cooling upon removal from the water bath. The cooling effect is occasioned by the expansion of the pressurized content escaping through the mechanism. The foregoing embodiment of the invention provides a guide 46 forming a part of valve 28 and which slides within bore 34. As shown in FIG. 5, an opening of the valve is guided so that the valve remains coaxial of bore 34 and easily returns to the closed position shown in FIG. 4 to properly reseat and reseal. Guide 46 forms a retainer for an O- ring 48 which seals the valve when it is closed.

In a second form of the invention, it is desired to prevent automatic reseating of the valve. In this embodiment once the horn begins to sound it continues to sound until the content of container 16 is exhausted. A use for this embodiment may be found in situations in which a fire may start in one place and rapidly move away to another location.

This second embodiment is provided as shown in FIG. 6 with angled seats for spring 32 so that the spring is not coaxial with bore 34. When the valve opens it is pushed sideways by the askew spring and does not reseat. To permit this sideways movement of the valve, guide 46 may be greatly reduced in size or eliminated altogether.

The foregoing is illustrative of preferred embodiments of the invention but other embodiments and modifications may be had within the teachings hereof.

For example, the coupling means utilized to join the valve means to the container is shown to be a threaded collar portion of valve seat 18; also shown, however, is a flange 60 which may be clamped to a corresponding flange 61 commonly found on containers of the type,

The pressurized content of the container could be a refrigerant, nitrogen, CO, or any other suitable product. Conveniently, there are replacement freon cartridges on the market which have relatively standard specifications including, for example, the threaded cap.

Whatl claim is:

l. A fire alarm, comprising in combination:

a. a horn;

b. a container including pressurized content;

c valve means, said valve means connecting between said horn and said container and comprising a valve spring urged against content pressure, whereby content pressure comprising:

a. a coupling, said coupling connecting between said container and said valve means and comprising a clampable flange; and

b. piercing means, said piercing means being mounted at said coupling for piercing contact with said container. 

1. A fire alarm, comprising in combination: a. a horn; b. a container including pressurized content; c. valve means, said valve means connecting between said horn and said container and comprising a valve spring urged against content pressure, whereby content pressure in excess of spring bias opens said valve and escapes through and sounds said horn, said valve means comprising: i. a valve seat having a central bore; ii. a spring, the axis of said spring being at an angle with respect to the axis of said bore; and iii. a valve, said valve being spring urged by said spring askew of said bore.
 2. A fire alarm in accordance with claim 1, additionally comprising: a. a coupling, said coupling connecting between said container and said valve means and comprising a clampable flange; and b. piercing means, said piercing means being mounted at said coupling for piercing contact with said container. 